Diesel fuels are generally divided into several main types, each suitable for different operating conditions. Knowing the different types of diesel fuel can help you choose the most suitable diesel fuel according to equipment needs and usage environment, so that the engine can perform more stably and efficiently.
What Are The Types Of Diesel Fuel?
There are several different types and grades of diesel fuels available. Each has its own set of benefits and drawbacks. Some of the types most used in equipment include:
#1 Diesel (Winter Diesel)
#1 Diesel is really suit for cold weather. It is lighter, more refined, and has a lower viscosity. That is, thinner and easier to flow than other grades of diesel. The biggest feature is that it contains almost no paraffin. Because paraffin wax waxes or hardens below freezing, it may block the fuel filter and oil path, preventing the engine from starting.
Since #1 diesel is also not easy to condense at extremely low temperatures (about -40°F or -40°C), it is very popular when operating in winter. It typically has a higher cetane number, making it easier to start the engine in cold weather and reducing the burden on the battery and starting motor. Many fuel suppliers also add lubricants and cleaners to #1 diesel to help protect the fuel system and keep the fuel injectors clean. Its only drawback is that its energy density is slightly lower than that of #2 diesel. So, power take-off and fuel economy may decrease slightly.
#2 Diesel (Regular Diesel)
For most diesel engines, #2 diesel is the standard general-purpose fuel. It has a higher oil content and higher viscosity than #1 diesel. This gives it two main advantages:
- High Energy: #2 diesel contains higher energy per gallon. When your machinery is running, #2 diesel can provide more power. In the face of heavy work, overall fuel efficiency is also higher.
- Excellent Lubricity: #2 diesel itself is oily and can provide necessary lubrication for high-pressure oil pumps and injectors. Less wear, protecting these expensive parts.
The low temperature is average: as soon as the temperature drops, the paraffin wax in #2 diesel will crystallize. Fuel oil tends to thicken or gel. This is the reason why the engine is difficult to start. If #2 diesel is not antifreeze-treated or not mixed with #1 diesel, it is not suitable for use in cold areas in winter.
Biodiesel Fuel
Now that all industries are looking for more environmentally friendly and sustainable fuels, biodiesel has become popular. It is renewable. The raw materials are vegetable oils (such as soybean oil), animal fat, and recycled cooking waste oil, which are not extracted from petroleum.
Biodiesel is mostly sold mixed with traditional petroleum diesel. The product label will have a “B” followed by a number representing the proportion of biodiesel in the blend.
- B5 (5% biodiesel, 95% petroleum diesel): Approved for use in almost all diesel engines without any modifications.
- B20 (20% biodiesel, 80% petroleum diesel): A common blend, but you must check your equipment manufacturer’s manual to ensure it is approved for your specific engine.
- B100 (100% pure biodiesel): Rarely used in heavy equipment without significant engine and fuel system modifications.
Biodiesel is particularly well lubricated and helps protect engine components. But for non-road machinery, it also has many disadvantages. Its low-temperature performance is usually worse than that of #2 diesel. It can also damage rubber fuel lines and seals. Biodiesel also absorbs water more easily. This will allow microorganisms to grow in the fuel tank. Therefore, the maintenance of the storage tank can be done well.
Off-Road Diesel (Dyed Diesel)
The chemical composition of off-road diesel is exactly the same as #2 diesel, with one difference— it is dyed red.
Why dye it? Dyed red, it was clear to the inspector that the fuel could only be used on non-road equipment. Because it is used for off-road equipment, there is no tax, and the price is much cheaper.
This fuel is specially used for equipment like excavators, bulldozers, tractors or others. Adding red diesel to road vehicles (such as construction trucks) could result in serious legal penalties, with fines running into the thousands of dollars. Dyeing is designed to make it easy for law enforcement to detect illegal use. For car owners with non-road equipment fleets, using this dyed diesel to power the equipment is standard operation and the most cost-effective.
What Is the Difference Between #1 and #2 Diesel?
Go to a gas station to fill up. The most common ones are #1 diesel and #2 diesel. Let’s directly compare these two main types of petroleum diesel. The key to choosing which one to choose is whether you value low-temperature operation or sufficient power. In fact, it is a trade-off between these two.
Their core differences are mainly in viscosity, energy content and cetane rating.
- Viscosity: Simply put, it means whether the fuel is thick or not. #1 Diesel fuel is thinner, has low viscosity, and can flow smoothly even when the weather is cold; #2 Diesel fuel is thicker, has high viscosity, and has a good lubrication effect, but as soon as the temperature drops, it is easy to condense.
- Energy Content:#2 diesel is denser and packs more energy. For machines, it’s more powerful and gets better fuel economy. #1 Diesel has a lower energy density, so you might notice slightly less performance.
- Cetane Rating: It tells you how fast the fuel burns after compression. Both diesels usually have a cetane number between 40 and 55, but #1 diesel is often a bit higher. So it starts quicker and smoother, especially when it’s cold, way more helpful than.
In summer, #2 diesel is the most suitable. It has strong power and good lubricity, making it an ideal choice. In winter, a fuel that does not wax easily is needed.
So many fuel suppliers will launch so-called “winter blend diesel”. Mix diesel #1 and #2 in proportion. This can maintain the advantage of #1 diesel not being easy to condense at low temperatures, while retaining a part of the power and lubricity of #2 diesel.
Knowing Diesel Fuel Quality
In addition to the base model, the overall quality of the diesel is particularly critical to protecting the engine. The quality mentioned here is whether the fuel burns well and whether it can protect the engine parts. The core looks at three things: cetane number, cleanliness and storage method.
- Cetane Number: A fuel’s cetane number measures its ignition quality. A higher number means the fuel ignites faster and burns more completely. Most diesel in the U.S. has a cetane number between 40 and 55. For heavy equipment, a fuel within this range ensures smooth startups and efficient operation. Fuel with a cetane number that is too high can ignite too early, while a number that is too low can cause hard starts and rough running.
- Fuel Cleanliness: Contaminants like water, dirt, and sediment can quickly destroy expensive injectors and fuel pumps. Water in fuel can also lead to microbial growth (often called “algae”), which clogs filters and starves the engine of fuel.
- Storage: If you have on-site fuel tanks, proper storage is vital. Ensure your tanks are sealed from the elements to keep water and dirt out. Regularly check for and drain any accumulated water from the bottom of the tank. Using quality fuel from a reputable supplier is the first step in ensuring your machinery gets clean, effective power.
Which Diesel Do I Choose?
So how do you choose diesel? Choosing the right fuel is good for the performance and life of your equipment. In short, we can consider these three aspects:
- Manufacturer’s Suggestions: Look through the device’s manual. Regardless of the brand, manufacturers will indicate which diesel is best for their engine and emissions system. Using inappropriate fuel (such as a high proportion of biodiesel blend) may affect engine performance.
- Climate and the Seasons: To work in particularly cold places, you have to use #1 diesel or winter blend diesel. In warmer regions and seasons, #2 diesel is generally used. It’s more powerful.
- Equipment Use and Load: If the machine often pulls heavy goods, then choose #2 diesel. If the equipment is mostly idle for a long time, add some fuel stabilizer to prevent the diesel from deteriorating over time.
Which Type of Diesel Fuel Costs Less?
In terms of price, #2 diesel is generally cheaper than #1 diesel because its refining process is simpler.
Don’t just look at the price tag, though. The cheapest fuel isn’t necessarily the option to really save money. For example, off-road diesel (usually red-dyed diesel) does not have to pay road tax, so the price will be much lower than ordinary transparent diesel. This is a very real cost-saving for all kinds of non-road equipment.
Sure, #1 diesel does cost more per gallon, but using it in the winter can save you the hassle of fuel waxing, equipment downtime, and even repairs. Compared with that, the extra money is actually a good deal. Besides, high-quality diesel burns cleaner and more efficiently, and can also reduce fuel system wear and tear, which can also save you a lot of maintenance costs in the long run.
Final Thought
There are some factors to consider when choosing fuel for equipment. Different diesel engines have different needs. Remember to read the manufacturer’s suggestions. Also, ask if you can use biodiesel or synthetic diesel as an alternative. In addition, no matter which type of diesel, parts such as the fuel pump, injector, and oil filter must be replaced regularly. FridayParts has a lot of high-quality replacement parts to help keep your diesel equipment in good performance.
FAQs About Diesel Fuel
Can I mix different diesel fuel grades?
Yes, this is common practice. Mixing #1 diesel and #2 diesel is actually how to make “winter diesel” or “blended diesel”. This balances low temperature crystallization and fuel efficiency. Even if you have some #2 diesel left in your tank, adding a winter mix is perfectly fine.
Which is the best diesel fuel?
No single diesel fuel is suitable for all situations, and there is no absolute “best” choice. The right fuel for your machine, for the season, is the best. In mild weather, #2 diesel is the best choice. In winter, winter special diesel or #1 diesel is better.
How does the cetane rating affect diesel fuel performance?
The cetane number measures how quickly diesel fuel ignites. The higher the cetane number, the faster the ignition starts. This facilitates a cold start, burns more fully, and has the potential to reduce emissions.
Why is winterized diesel important?
Cold-weather running, winter diesel is important. It prevents fuel condensation and prevents waxy crystals from blocking filters. As soon as the fuel condenses, the equipment stops.
What is the most common type of diesel fuel?
The most commonly used for off-highway machinery is dyed #2 diesel. It has plenty of energy, good lubrication, and is tax-free. It is very suitable for non-road industries such as construction and agriculture, and is also cost-effective.
